This invention relates to a press brake capable of measuring a bent form, such as a bent angle and bending radius without ejecting a workpiece on which bending is performed and efficiently correcting the bending angle of a workpiece on the basis of the measurement without any hand operation, and further relates to the workpiece measuring method.
In a case where a workpiece is bent in a V-form or an arc-form in a press brake, a predetermined bending is performed by inserting a workpiece between lower and upper dies. It is then measured whether the bent form of the machined workpiece, such as the bending angle and bending radius, is a set value or not. On this occasion, when the bent form is measured in a state with the machined workpiece in a press brake, it is impossible to measure correctly due to the presence of the lower die and the like. Therefore, the bent form is measured by ejecting the machined workpiece from between the upper and lower dies of a press brake in a conventional method. In a case where the measured bent form is different from a set value, remachining is performed on the workpiece by replacing it in the press brake to vary the form. In this way, correction is performed so that the measured value can be a set value. However, it is necessary to eject the workpiece from the press brake for every measurement of the bent form of the workpiece in this method. This causes reduction of machining efficiency. Besides, correction operations for remachining depend heavily on the experience of the worker. Therefore, in a case where a worker isn't skilled, it is difficult to decide the proper amount of correction quickly. Thus, the operations require much labor and time.